Circuit arrangement for generating oscillations



Patented Jan. 18, 1927.

UNiTED STATES Param orifice- HANS RUKOP, 0F BERLIN, GERMANY, .AS-SIGNOR TQGESELLSCI-IAFT FR :DRAHTLOSE TELEGRAPHIE M. IB. H. HALLESCHES, CF BERLIN, GERMANY, A CORPORATION OF GERMANY.

CIRCUIT ARRANGEMENT FOR GENERATING- CSCILLA'IIONS.

Applcationled December 27,1922, Serial No. 609,185, and in Germany February 11, 192,2.

rIhe German Patent, No. 304,283, describes special circuit arrangements for generating continuous electrical oscillations tor the purpose oi keeping` sending waves as constant as possible notwithstanding variations in the circuits, tor example, variations dueto poor antennae. It is known that thel natural wave length ot an antenna circuit may vary over a wide range due to change in the position o1- the antenna relative to the ground and other objects, due to winds, etc. The arrangement is so lconstituted that the energy which is used up is derived mainly trom one circuit, whereas the Wave length is determined by a second additional systen'i which is maintained as constant as possible.

rlhe present application pertains to a special circuit arrangement operating according to like principles.

In the drawings Fig. 1 shows the circuit arrangement asa whole and Fig. 2 shows the relation between the wave lengths of the two coupling waves produced in two coupled tuned circuit and the factors varying the wave length of one ot those cir cuits.

In accordance with the present invention, an oscillating circuit is provided for supplying the energy, e. g. an antenna circuit I, and a second oscillating circuit II is provided which is tree of losses and is constant. The circuit arrangement as a whole may be as shown in Figl, i. e. vlike that shown in Fig. l ot saidpatent. The circuit consists ot' a three element therinionic tube T having the circuit II connected across its grid and cathode. The circuit II consists of an inductance l and capacitance 2 connected in parallel which are kept constant `under operating conditions. Connected a'crossanode and cathode is inductance 3 which is coupled to inductance 1 tor producing sustained oscillations in the well-known way, and anode supply direct current generator 4.

Connected also across the anode and cathode is the primary ot transformer 5 in series witlicondenser 6. The secondary of transformer 5 is connected in the antenna circuit.

It will be seen that the two circuits I and II may he loosely or closely coupled with each other depending on the values ot the circuit arrangement.

In accordance with the present invention, first, the two circuits are noticeably detuiied with respect to each other, second, the coupling of the two circuits is somewhat close, that is to say, not very loose, and, third, the back-coupling` between the circuits, or any auxiliary means in its stead, is provided in such a manner that oi the wave lengths that may come out ot the coupling circuit only that one will energizeitselt which is near the individual natural wave ot' the constant circuit II and not that one which is near thev natural wave ot the variablecircuit I.

The last-mentioned condition is based upon the well known tact, that if two circuits of different natural wave-lengths be coupled together, the resonance points are not at the natural wavelengths ot thesingle circuits, but the resonance curve ot the resultant circuit arrangementY will be found to have two peaks. For convenience I have designated the wavelengths of these two peaks as coupling Waves7 or` coupling wavelengths. @ne coupling wave is vlonger than the longest of the two individual natural waves but is quite near to it. On the other hand, the other' coupling wave is shorter than the shortest otv the two individual natural waves and is equally near to it. rlhesubstantially constant character of the sending wave length enables the coupling wave which, as explained above and .in accordance with the above stated conditions, is very near the `individual natural wave of the constant circuit II, .toY be made independent of the individual natural wave of the circuit I, so as not vtov be appreciably affected by variations in the'circuit I. This relation is illustrated in Fig. 2, in which itis assumed that vthe natural wave length ot the circuit II is constant and that the natural wave length ot the circuit I is variable witliin wide limi-ts. The conditions which cause variations in the natural wave length of the circuit I, including variable capacityor seltinduetion, serve as the abscissa. The: ordinate represents wavelength.

The line A-A denotes the individual natl ie.

ural wave length of the circuit I, which varies in proportion with the changes in the conditions represented by the abscissa. ihe line B-B denotes the natural wave length of the circuit II which is constant. The wave lengths which may be actually generated in the system are shown by C and D. ylhe system is operated at one of the points in the diagram which show a considerable constancy of the energized wave lengths notwithstanding variations in the natural wave length of the circuit I, e. g. around P or Q. rI`he longer wave C appears as constant in the neighborhood ot lD and the shorter wave D in the neighborhood ot' Q notwithstanding the variations in circuit I.

, It will be see-n, therefore, that in accordance with the above principle the constant circuit may either have a natural wave length greater than that of the variable circuit as at P or smaller as at Q. It is advisable to use a back-coupling arrangemeut which prevents the cutting over of the sender into the other coupling wave.

rlhe manner in which these circuits are coupled, that is to say, whether they are electrically or mechanically coupled or whether special intermediate elements such as coils or inductances are used, is without any importance from the standpoint of the present invention.

Having described my invention what I claim is:

l. In a vacuum tube oscillation generator having an input and output circuit regeneratively coupled, the combination of a first circuit having a firstl natural wavelength, a second circuit having a. second natural wavelength which is substantially different from said first wavelength, coupling means such that when said first and second circuits are taken together they have coupling wavelengths, and means for impressing one of said coupling wavelengths upon the input circuit of the generator.

2. In a vacuum tube oscillation generator having an input and output circuit regeneratively coupled the combination of a iirst circuit having a first natural wavelength, a second circuit having a second natural wavelength which is substantially different from said first wavelength, coupling means such that when said first and second circuits are taken together they have coupling wavelengths, and means whereby one of said coupling wavelengths is accentuated.

3. In a vacuum tube oscillation generator having an input and output circuit regeneratively coupled the combination of a first circuit having` a first natural wavelength, a. second circuit having a second natural wavelength which is substantially different that when said first and second circuits are taken together thev have coupling wavelengths, and amplifying means associated with said first circuit rilierxby only the coupling wavelength which is nearest said first wavelength is amplified.

5. In combination, an oscillator having its input and output circuits regeneratively coupled to produce sustained oscillations, one of' said circuits having a first natural wave length, a third circuit coupled to the other of said two` first mentioned circuits, and having a second natural wave length which is substantially different from said first Wave length, means for coupling said circuits hai/'ing natural wave lengths to produce coupled wave lengths, and means for radiating the coupled wave length which is nearest to said first mentioned wave length.

6. In combination, an oscillator having its input and output circuits regeneratively coupled to produce sustained oscillations, said input circuit having a first natural wavelength, a work circuit coupled to said output circuit and having a second natural wavelength which is substantially dill'erent from said first wavelength, said coupled circuits talen together having coupling wavelengths, and means whereby only the one of the resulting couping wavelengths which is nearest the first natural wavelength is generated.

7. In combination, a thermionic tube having an anode, grid and cathode, a first circuit cmprising an inductance and a source of direct currentin series with said anode and cathode, a grid circuit comprisng an inductance and capacitance in parallel connectedbetween said grid and cathode, said inductances being coupled to each other, said grid' circuit having a first natural wavelength, asecond circuit connected in series with said anode and cathode, an antenna circuit coupled to said second circuit and having a natural wave length substantially different from said rst wavelength, whereby only the one of the coupling wavelengths resulting from the interaction of the circuits on each other which is -nearest the first natural wavelength is generated.

HANS RUKOP.

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